From the Guidelines
The stability of an OCD lesion is determined by the presence of a hyperintense rim or cysts at the osteochondral fragment periphery on MRI, although this is less specific in children compared to adults.
Key Factors
- A hyperintense rim or cysts at the osteochondral fragment periphery on MRI are indicators of OCD fragment instability, but with lower specificity in children 1.
- MRI is useful in determining the best method of treatment and can grade the repair site after cartilage repair 1.
- The presence of structural abnormalities, such as synovitis or effusion, can also be indicative of OCD lesion instability, but may not always discriminate between painful and nonpainful knees 1.
Imaging Modalities
- MRI is a valuable tool in evaluating OCD lesions, particularly in determining the stability of the lesion and guiding treatment options 1.
- CT is the most accurate method for evaluating cartilage abnormalities extending to the articular surface, but MRI is still useful for determining treatment and grading repair sites 1.
- Radiography may not be sufficient for evaluating OCD lesions, especially in cases where symptoms are not explained by radiographic findings 1.
From the Research
Determinants of OCD Lesion Stability
The stability of an OCD (Osteochondritis Dissecans) lesion is determined by several factors, including:
- Lesion size and thickness of the sclerotic margin as measured on plain radiographs 2
- Presence of a displaced fragment, epiphyseal closure of the capitellum, or a lateral epicondyle observed on radiographs 3
- Irregular contours of the articular surface or a high signal interface on T2-weighted MRI 3
- Displaced fragment observed on CT scans 3
- Intralesional segmentation, which is sensitive for detecting an unstable lesion 3
Imaging Modalities for Assessing Lesion Stability
Different imaging modalities can be used to assess the stability of an OCD lesion, including:
- Plain radiography, which can provide information on lesion size and sclerotic margin thickness 2, 3
- MRI, which can provide detailed information on lesion morphology and stability 4, 2, 3
- CT scans, which can provide information on fragment displacement and intralesional segmentation 3
- Bone scintigraphy, which can be more sensitive and specific in determining mechanical stability than plain radiography 2
Clinical Implications of Lesion Stability
The stability of an OCD lesion has important clinical implications, including:
- Treatment decisions, with stable lesions potentially being treated non-surgically and unstable lesions requiring surgical management 5, 6
- Prognosis, with unstable lesions being more likely to lead to premature degeneration of the joint if left untreated 6
- Potential for healing, with stable lesions having a greater propensity to heal with non-surgical treatment, particularly in juvenile patients 6